package httpfetcher

import (
	"errors"
	"net"
	"testing"
	"time"
)

// TestNewUsesCheckedDialerWithoutDialContext checks that a fetcher built
// without DialContext, as pixa builds it, refuses to connect to a local
// server.
func TestNewUsesCheckedDialerWithoutDialContext(t *testing.T) {
	t.Parallel()

	srv := startUpstream(t)
	transport := transportOf(t, New(&Config{
		Timeout:               30 * time.Second,
		MaxResponseSize:       50 << 20,
		MaxConnectionsPerHost: 20,
		MaxConnections:        64,
	}))

	addr := srv.Listener.Addr().String()

	_, err := transport.DialContext(testContext(t), "tcp", addr)
	if !errors.Is(err, ErrSSRFBlocked) {
		t.Fatalf("DialContext(%s) error = %v, want ErrSSRFBlocked", addr, err)
	}
}

// TestDialContextReplacesOnlyTheDialer checks that a fetcher built with
// DialContext connects through it, while the URL check still refuses a
// loopback URL and the redirect check a redirect to a link-local address.
func TestDialContextReplacesOnlyTheDialer(t *testing.T) {
	t.Parallel()

	srv := startUpstream(t)
	dialer := &recordingDialer{target: srv.Listener.Addr().String()}

	f := New(&Config{
		Timeout:               30 * time.Second,
		MaxResponseSize:       50 << 20,
		AllowHTTP:             true,
		MaxConnectionsPerHost: 20,
		MaxConnections:        64,
		DialContext:           dialer.dialContext,
	})

	if body := fetchBody(t, f, "/image"); body != imagePayload {
		t.Errorf("body = %q, want %q", body, imagePayload)
	}

	_, err := f.Fetch(testContext(t), imageSourceOn("127.0.0.1"))
	if !errors.Is(err, ErrSSRFBlocked) {
		t.Errorf("Fetch(loopback URL) error = %v, want ErrSSRFBlocked", err)
	}

	_, err = f.Fetch(testContext(t), upstreamSource("/redirect/private"))
	if !errors.Is(err, ErrSSRFBlocked) {
		t.Errorf("Fetch(/redirect/private) error = %v, want ErrSSRFBlocked", err)
	}

	// The upstream server is reached through DialContext, and nothing else
	// is asked of it.
	dialed := dialer.dialedAddrs()
	if len(dialed) == 0 {
		t.Error("DialContext was never called")
	}

	for _, addr := range dialed {
		if addr != net.JoinHostPort(testPublicHost, "80") {
			t.Errorf("DialContext was asked to connect to %s", addr)
		}
	}
}